A sample of Ar gas at 1 atm pressure and $27^{\circ}C$ expands reversibly and adiabatically from $1.25\: dm^3\: to\: 2.5\: dm^3$. Calculate enthalpy change of this process. $CV$ for argon is $12.4\: kJ/mol$

Question

$\begin {array} {1 1} (A)\;1145.7 \: J & \quad (B)\;-1145.7 \: J \\ (C)\;114.57 \: J & \quad (D)\;-114.57 \: J \end {array}$